Instituto Nacional Of Investigacao E Desenvolvimento Agrario

Praia, Cape Verde

Instituto Nacional Of Investigacao E Desenvolvimento Agrario

Praia, Cape Verde
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Caujape-Castells J.,University of Las Palmas de Gran Canaria | Tye A.,Secretariat of the Pacific Regional Environment Programme | Crawford D.J.,Biodiversity Research Center | Santos-Guerra A.,Instituto Canario Of Investigaciones Agrarias | And 8 more authors.
Perspectives in Plant Ecology, Evolution and Systematics | Year: 2010

Current threats to the planet's biodiversity are unprecedented, and they particularly imperil insular floras. In this investigation, we use the threat factors identified by the Millennium Ecosystem Assessment as the main drivers of biodiversity loss on islands to define and rank 13 current, continuing threats to the plant diversity of nine focal archipelagos where volcanic origin (or in the Seychelles a prolonged isolation after a continental origin) has produced a high degree of endemicity and fragility in the face of habitat alteration. We also conduct a global endangerment assessment based on the numbers of insular endemic plants in the endangered (EN) and critically endangered (CR) IUCN categories for 53 island groups with an estimated 9951 endemic plant species, providing a representative sample of the world's insular systems and their floristic richness. Our analyses indicate that isolation does not significantly influence endangerment, but plant endemics from very small islands are more often critically endangered. We estimate that between 3500 and 6800 of the estimated 70,000 insular endemic plant species worldwide might be highly threatened (CR+EN) and between ca. 2000 and 2800 of them in critical danger of extinction (CR). Based on these analyses, and on a worldwide literature review of the biological threat factors considered, we identify challenging questions for conservation research, asking (i) what are the most urgent priorities for the conservation of insular species and floras, and (ii) with the knowledge and assets available, how can we improve the impact of conservation science and practice on the preservation of island biodiversity? Our analysis indicates that the synergistic action of many threat factors can induce major ecological disturbances, leading to multiple extinctions. We review weaknesses and strengths in conservation research and management in the nine focal archipelagos, and highlight the urgent need for conservation scientists to share knowledge and expertise, identify and discuss common challenges, and formulate multi-disciplinary conservation objectives for insular plant endemics worldwide. To our knowledge, this is the most up-to-date and comprehensive survey yet to review the threat factors to native plants on oceanic islands and define priority research questions. © 2009 Rübel Foundation, ETH Zürich.

De Pina Tavares J.,Instituto Nacional Of Investigacao E Desenvolvimento Agrario | Ferreira A.J.D.,Polytechnic Institute of Coimbra | Reis E.A.,Instituto Nacional Of Investigacao E Desenvolvimento Agrario | Baptista I.,Instituto Nacional Of Investigacao E Desenvolvimento Agrario | And 4 more authors.
Land Degradation and Development | Year: 2014

Desertification is the most disturbing and detrimental cause of rural vulnerability in Cape Verde, affecting families' material and environmental resources. Combating desertification in Cape Verde is complex because it involves addressing a mixture of endogenous (manual agriculture, fuel wood and fodder extraction, land tenure and steep slopes) and exogenous drivers (high rainfall variability, climate change, prolonged drought or heavy rainfall). To address and mitigate the adverse effects of desertification, it is necessary to develop an approach that identifies and brings together all the key stakeholders affected by and acting on the desertification issue, including land users, policy makers, managers, researchers and rural development technicians. This paper presents a hybrid methodology based on global best practices, applied in Cape Verde. It combines experiences and skills of local stakeholders (farmers, local association of land users and local non-governmental organizations) with scientific knowledge of external stakeholders such as technicians of the Ministry of Rural Development, environmental advisors of Municipalities and researchers. Integration takes place following a participatory process of appraising and selecting desertification control strategies. The paper presents the first results obtained from application of the hybrid methodology to Ribeira Seca, the largest watershed of Santiago Island. The approach was evaluated with local and external stakeholders. Both groups appreciated that they could voice their views and discuss ways to overcome barriers and also to take full advantage of the opportunities offered by jointly selected promising desertification mitigation options. © 2013 John Wiley & Sons, Ltd.

Baptista I.,Instituto Nacional Of Investigacao E Desenvolvimento Agrario | Baptista I.,Wageningen University | Ritsema C.,Wageningen University | Querido A.,United Environment & Energy, Llc | And 2 more authors.
Geoderma | Year: 2014

Dryland agriculture in Cabo Verde copes with steep slopes, inadequate practices, irregular intense rain, recurrent droughts, high runoff rates, severe soil erosion and declining fertility, leading to the inefficient use of rainwater. Maize and beans occupy >80% of the arable land in low-input, low-yielding subsistence farming. Three collaborative field trials were conducted in different agroecological zones to evaluate the effects of water-conservation techniques (mulching of crop residue, a soil surfactant and pigeon-pea hedges) combined with organic amendments (compost and animal or green manure) on runoff and soil loss. During the 2011 and 2012 rainy seasons, three treatments and one control (traditional practice) were applied to 44- and 24-m2 field plots. A local maize variety and two types of beans were planted. Runoff and suspended sediments were collected and quantified after each daily erosive rainfall. Runoff occurred for rainfalls ≥50mm (slope <10%, loamy Kastanozem), ≥60mm (slope ≤23%, silt-clay-loam Regosol) and ≥40mm (slope ≤37%, sandy loam Cambisol). Runoff was significantly reduced only with the mulch treatment on the slope >10% and in the treatment of surfactant with organic amendment on the slope <10%. Soil loss reached 16.6, 5.1, 6.6 and 0.4Mgha-1 on the Regosol (≤23% slope) for the control, surfactant, pigeon-pea and mulch/pigeon-pea (with organic amendment) treatments, respectively; 3.2, 0.9, 1.3 and 0.1Mgha-1 on the Cambisol (≤37% slope) and <0. 2Mgha-1 for all treatments and control on the Kastanozem (<10% slope). Erosion was highly positively correlated with runoff. Mulch with pigeon-pea combined with an organic amendment significantly reduced runoff and erosion from agricultural fields on steep slopes, contributing to improved use of rainwater at the plot level. Sustainable land management techniques, such as mulching with pigeon-pea hedges and an organic amendment, should be advocated and promoted for the semiarid hillsides of Cabo Verde prone to erosion to increase rainwater-use and to prevent further soil degradation. © 2014 Elsevier B.V.

Baptista I.,Instituto Nacional Of Investigacao E Desenvolvimento Agrario | Baptista I.,Wageningen University | Ritsema C.,Wageningen University | Geissen V.,Wageningen University | Geissen V.,University of Bonn
PLoS ONE | Year: 2015

Soil erosion, runoff and related nutrient losses are a big risk for soil fertility in Cabo Verde drylands. In 2012, field trials were conducted in two agro-ecological zones to evaluate the effects of selected techniques of soil-water management combined with organic amendments (T1: compost/manure + soil surfactant; T2: compost/animal or green manure + pigeon-pea hedges + soil surfactant; T3: compost/animal or green manure + mulch + pigeon-pea hedges) on nitrogen (N) and phosphorus (P) losses in eroded soil and runoff and on crop yields. Three treatments and one control (traditional practice) were tested in field plots at three sites with a local maize variety and two types of beans. Runoff and eroded soil were collected after each erosive rain, quantified, and analysed for NO3-N and PO4-P concentrations. In all treatments runoff had higher concentrations of NO3-N (2.20- 4.83 mg L-1) than of PO4-P (0.02-0.07 mg L-1), and the eroded soil had higher content of PO4-P (5.27-18.8 mg g-1) than of NO3-N (1.30-8.51 mg g-1). The control had significantly higher losses of both NO3-N (5.4, 4.4 and 19 kg ha-1) and PO4-P (0.2, 0.1 and 0.4 kg ha-1) than the other treatments. T3 reduced soil loss, runoff and nutrient losses to nearly a 100% while T1 and T2 reduced those losses from 43 to 88%. The losses of NO3-N and PO4-P were highly correlated with the amounts of runoff and eroded soil. Nutrient losses from the applied amendments were low (5.7% maximum), but the losses in the control could indicate long-term nutrient depletion in the soil (19 and 0.4 kg ha-1 of NO3-N and PO4-P, respectively). T1-T3 did not consistently increase crop yield or biomass in all three sites, but T1 increased both crop yield and biomass. We conclude that T3 (combining crop-residue mulch with organic amendment and runoff hedges) is the best treatment for steep slope areas but, the pigeon-pea hedges need to be managed for higher maize yield. T1 (combining organic amendment with soil surfactant) could be a better choice for flatter areas with deeper soils. © 2015 Baptista et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

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